This invention relates to a force-controlled throttle for adjusting the engine thrust of a combat aircraft.
In a combat aircraft, the engine thrust is regulated by the pilot via the throttle, i.e., a manually operated thrust lever (also known as a throttle lever). The normal control range is from idling to full thrust (max dry, i.e., without afterburner fuel injection). In addition, if an afterburner is provided, it may be turned on, regulated and turned off (min/max afterburner). The thrust lever is traditionally adjusted for a length of approximately 150 to 200 mm for this purpose.
The throttle should fulfill various ergonomic requirements regarding the force, displacement and movement characteristics so that the pilot can adjust the thrust quickly and accurately. In a landing, for example, very precise and accurate information must be input. The throttle must not jerk. However, unintentional input should be avoided, so the force required to make an adjustment should not be too low. The afterburner must be clearly separated, so that unintentional selection of the afterburner is impossible. These requirements have resulted in the development of complex and expensive electronic throttles known as force feedback throttle units.
A throttle is presumed as already known, i.e., a thrust lever for adjusting the engine thrust of a combat aircraft having a handle for operation by a pilot and a signal generating device connected to the handle for generating a control signal that is used to adjust the engine thrust.
Throttles of this type that are known currently operate with a lever which supports the handle and is connected to the signal generating device; this lever is mounted so it is linearly or rotatably displaceable about an axis in the manner of a rotating movement.
The engines in modern airplanes are regulated electronically (by wire) and nevertheless the type of operation based on the requirements of older planes in which the engines are regulated by a lever system (e.g., MiG 29) has been retained. Traditionally the afterburner range is separated via a crank (lateral movement of the handle) or by an additional force that must be overcome or by an additional lever to be operated. However, there are some disadvantages to this conventional design, based on the requirements of a modern combat aircraft. Friction in the mechanics prevents accurate input. Devices having mechanical friction brakes require frequent maintenance and adjustment work. In a trainer aircraft, the throttles must be connected so they are all in the same position. In addition, the instructor must have the opportunity to take over the controls completely. With a mechanical linking of the throttles, this may be accomplished only with considerable effort by means of a lever system between the front cockpit and the rear cockpit.
The object of this invention is to create an improved throttle for adjusting the engine thrust of a combat aircraft.
This object is achieved according to this invention by a power throttle having a handle and a signal generating device for generating a control signal used for adjusting the engine torque, wherein the signal generating device generates the control signal as a function of the force exerted on the handle by the pilot in operation.
This invention creates a force-controlled throttle for adjusting the engine thrust of a combat aircraft with a handle for operation by a pilot and a signal generating device connected to the handle for generating a control signal for adjusting the engine thrust. According to this invention, the signal generating device is provided for generating the control signal as a function of the force exerted on the handle in operation by the pilot.
Thus the inventive solution consists of a force-controlled throttle which hardly moves at all in comparison with the traditional displacement-controlled thrust levers. The thrust is controlled on the basis of the force exerted on the throttle. Pushing forward increases the engine power, whereas pulling toward the rear reduces it. Because of the small movement, the throttle handle can be separated by a lever arm from the mechanism, i.e., the signal generating device which is connected to the handle. The throttle handle can be arranged at the optimum height (at the same level as the pilot's heart). The throttle mechanics can be installed separately in the side wall of the cockpit. This creates additional space for displays and controls in the cockpit. Because of the small size, this throttle can be installed by retrofitting an existing aircraft. It is particularly advantageous that the engine may be regulated very accurately through precise input.
According to a particularly preferred embodiment of the inventive force-controlled throttle, the signal generating device comprises an elastic actuator element which is resilient in response to the force exerted by the pilot and a signal generator which is functionally connected to the actuator element for generating the control signal so that it represents the force exerted by the pilot on the handle, and comprises an actuator signal generating device whose signal is connected to the signal generator for generating from the control signal an actuator signal that represents the absolute value of the engine thrust to be adjusted.
The actuator element here is preferably arranged so that it is movable over a predetermined actuator displacement according to a force exerted by the pilot, and the signal generator functionally linked to the actuator element is provided for generating a control signal that corresponds to the actuator displacement.
The actuator element is preferably pivotably or displaceably mounted and is connected to a spring device which generates an opposing force which counteracts the movement over the predetermined actuator displacement.
According to a preferred embodiment of this invention, the actuator element is arranged so that it is movable starting from a force-free basic position in a first direction or in a second direction opposite the first direction according to the force exerted by the pilot, whereby the signal generator is provided for a movement in the first direction to generate control signals in the sense of an increase in the engine thrust and for a movement in the second direction to generate control signals in the sense of a reduction in engine thrust.
According to another preferred embodiment of this invention, the signal generator generates a control signal which changes steadily with the size of the actuator displacement.
According to a preferred embodiment of this invention, it is also provided that the actuator element is movable in the first direction between the basic position and a first stop, which corresponds to a maximum force in the first direction, and in the second direction between the basic position and a second stop, which corresponds to a maximum force in the second direction, whereby the signal generator generates control signals corresponding to an increase in engine thrust when the actuator element is moved in the first direction and corresponding to a reduction in engine thrust when the actuator element is moved in the second direction.
According to another preferred embodiment of this invention, it is provided that for aircraft having an afterburner, a first defined position is provided in the actuator displacement of the actuator element in the first direction between the basic position and the first stop beyond which the actuator displacement can be increased in the first direction only when a definite discontinuous increase in the force exerted by the pilot, such that when the afterburner has been turned off, the signal generator generates a control signal corresponding to turning the afterburner on when there is an increase in the actuator displacement beyond the defined position.
According to a preferred embodiment of this invention, a second defined position is provided in the actuator displacement of the actuator element in the second direction between the basic position and the second stop; beyond this second defined position, the actuator displacement of the actuator element in the second position can be increased only with a definite discontinuous increase in the force exerted by the pilot, whereby when the afterburner is turned on and the actuator displacement is increased beyond the second defined position, the signal generator generates a control signal corresponding to turning off the afterburner. According to a preferred embodiment of this invention, when the afterburner is turned off, movement of the actuator element in the first direction between the basic position and the first defined position corresponds to an increase in the engine thrust up to maximum thrust without the afterburner.
According to a preferred embodiment of this invention, a movement of the actuator element in the first direction between the basic position and the first defined position when the afterburner is turned on corresponds to an increase in the engine thrust up to maximum thrust with the afterburner.
Preferably a movement of the actuator element in the second direction between the basic position and the second defined position when the afterburner is turned off corresponds to a reduction in the engine thrust to idling.
When the afterburner is turned on, a movement of the actuator element in the second direction between the basic position and the second defined position preferably corresponds to a reduction in the engine thrust down to minimal thrust with the afterburner.
According to a preferred embodiment of this invention, the actuator element is formed by a lever arm of a lever mounted to rotate about an axis of rotation, the end of the lever supporting the handle operated by the pilot.
The lever is preferably a two-way lever mounted to rotate about an axis of rotation provided in the central area, its one lever arm carrying the handle to be operated by the pilot and its other lever arm forming the actuator element.
According to a preferred embodiment of this invention, the spring device is formed by spring elements coupled to the actuator element in the direction of movement of the actuator element.
According to a particularly preferred embodiment of this invention, the spring elements are arranged in pairs on opposite sides on both ends of the actuator element in the direction of movement of the actuator element.
According to a particularly preferred embodiment of this invention, a first pair of spring elements and a second pair of spring elements are provided, arranged in pairs on both sides of the actuator element opposite one another in the direction of movement of the actuator element, with the first pair of spring elements generating a counterforce which increases steadily between the basic position and the first and second stops on the actuator element against the force exerted by the pilot on the handle, and the second pair of spring elements generating an additional counterforce when the first and/or second defined position is exceeded.
The first pair of spring elements is preferably situated a greater distance away from the axis of rotation and the second pair of spring elements is preferably situated closer to the axis of rotation.
According to a preferred embodiment of this invention, the spring elements include a spiral spring, a plunger connected between the spiral spring and the actuator element and a pressure plate which is displaceable by means of a threaded pin in the sense of a change in the spring bias.
The spring device preferably generates a spring bias suitable for creating a breakout force appropriate for moving the actuator element out of the basic position.
The signal generator is preferably formed by a linear potentiometer.
The linear potentiometer may be connected to the actuator element by an operating pin.
The signal generating device may be formed by an onboard computer of the aircraft or by a separate electronic switch.
According to a preferred embodiment of this invention, the spring elements and the signal generator are arranged in a housing box on which is also rotatably mounted the lever which carries the actuator element and the handle.
According to a preferred embodiment of this invention, the housing box is bordered by two opposing housing plates arranged on opposite sides of the actuator element and extending parallel to the direction of movement of the actuator element with the spring elements and the signal generator being mounted on the plates.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.